Thermal processing system

ABSTRACT

A thermal processing system performs predetermined thermal processing on an approximately circular to-be-processed object, by applying radiant heat to the to-be-processed object by means of a heating lamp system. The heating lamp system comprises a plurality of lamps disposed concentrically so as to correspond to the to-be-processed object. The plurality of lamps are controlled individually for respective zones of the to-be-processed object.

TECHNICAL FIELD

[0001] The present invention relates to a system for performing thermalprocessing, such as annealing processing, CVD (Chemical VaporDeposition) or the like, on a to-be-processed object, such as asemiconductor wafer, for example, by using a heating lamp system.

BACKGROUND ART

[0002] In general, in order to manufacture a semiconductor integratedcircuit, various thermal processes such as a deposition process, anannealing process, an oxidization and diffusion process, a spatteringprocess, an etching process, a nitriding process and so forth areperformed several times repeatedly on a silicon substrate such as asemiconductor wafer.

[0003] In this case, in order to maintain electric characteristics ofthe integrated circuit and throughput of the products to high level, theabove-mentioned various thermal processes should be performed on theentire surface of the wafer more uniformly. For this purpose, becausethe progress of the thermal process remarkably depends on thetemperature of the wafer, the temperature of the wafer should be uniformthroughout the entire surface thereof at high accuracy in the thermalprocessing.

[0004] In order to maintain the temperature of the wafer uniformthroughout the entire surface thereof, various methods are known. Forexample, in one method used in a single-wafer-type thermal processingsystem, a placement table on which a semiconductor wafer is placed isrotated so that occurrence of unevenness in temperature is avoided.

[0005]FIGS. 1 and 2 show two examples of thermal processing systems inthe related art.

[0006] In FIG. 1, in a processing chamber 2 in which a vacuum can beproduced, a thin placement table 4 is set which is supported on a bottomof the chamber 2, on which table a semiconductor wafer W is placed. Ashower head part 6 for providing a necessary processing gas such as adeposition gas into the processing chamber 2 is set on a top of theprocessing chamber 2. Further, on a bottom of the processing chamber 2,a transmitting window 8 made of a quarz glass, for example, is mountedin an airtight manner, and, beneath it, a plurality of heating lamps 10such as halogen lamps, for example, are mounted on a rotational table 12which also serves as a reflective plate. The wafer W is heated from therear side thereof by means of radiant heat from the heating lamps 10while the rotational table 12 is rotated. Thereby, it is attempted toheat the surface of the wafer W uniformly.

[0007] In a thermal processing system shown in FIG. 2, a gas providingnozzle 14 for providing a processing gas is provided in a side wall ofthe processing chamber 2 on one side, while a discharge mouth 16 forproducing a vacuum is provided on the other side. Transmitting windows18 and 20 made of a quarz glass are provided on a top and a bottom ofthe processing chamber 2. Further, above the upper transmitting window18 and beneath the lower transmitting window 20, heating lamps 22 aredisposed, and, thereby, the wafer W is heated from both top and bottomsides thereof. The placement table 4 is supported on a rotational shaft24 passing through a bottom plate of the processing chamber 2 in anairtight manner, and, as a result, is rotatable. In this system, whilethe wafer W is rotated, the wafer W is heated from both sides, and,thus, it is attempted to heat the surfaces of the wafer W uniformly.

[0008] In the system shown in FIG. 1, the heating lamps 10 are rotated.However, this system has a configuration such that a gate valve 26 isprovided in the side wall of the processing chamber 2 for bringing inthe wafer W. Accordingly, there is not a necessarily sufficient isotropyin view of temperature. As a result, it may not be possible to achieve asufficiently uniform temperature distribution throughout the surface ofthe wafer W.

[0009] In the system shown in FIG. 2, as the wafer W itself is rotated,isotropy in temperature of the side wall of the processing chamber 2 maybe not so problematic. However, as the upper transmitting window 18 hasa very high temperature due to radiant heat from the heating lamps 22and from the wafer W, especially in a case of a deposition process, adeposition film or a reaction by-product may adhere to this transmittingwindow 18, by which the luminous intensity transmitted by thetransmitting window 18 may be changed, and, as a result, repeatabilitymay be degraded, or particles may be generated therefrom. Further,although N₂ purge such as providing an inert nitrogen gas little bylittle toward the rear surface of the placement table 4 is performed,there is also a possibility, even fewer, that such a problem as theadherence of a deposition film or a reaction by-product occurs for thelower transmitting window 20.

[0010] Further, this problem of adherence of a deposition film or areaction by-product may also occur for the inner wall of the processingchamber 2 as it has a high temperature. Accordingly, it is necessary toperform cleaning of the processing chamber 2 frequently.

[0011] Furthermore, each of the above-mentioned transmitting windows 8,18 and 20 has a large thickness for the purpose of increasing a pressureresistively thereof. As a result, the heat capacity thereof is large,and, thereby, controllability of the temperature of the wafer Wtherethrough is degraded. Further, the distance between the heatinglamps and wafer W increases as the thickness of the transmitting windowincreases. As a result, the directivity of the heating lamps isdegraded.

[0012] In order to improve the directivity of the heating lamps, it iseffective to shorten the distance D between the surface of the wafer Wand the heating lamps (22, for example in FIG. 2) so that diffusion ofthe radiant heat of the heating lamps is reduced.

[0013] For example, FIGS. 3A and 3B are graphs showing relationshipsbetween the directivity of the heating lamps and the above-mentioneddistance D. FIG. 3A shows the directivity for D of 55 mm, while FIG. 3Bshows the directivity for D of 35 mm. Each curve in the figuresrepresents a temperature dependency on the wafer for a respectiveheating lamp. As can be seen from the figures, in the case of FIG. 3A,the peak of each curve is gentle. Accordingly, the number of heatinglamps contributing to heat a specific zone of the wafer is large, and,thus, the directivity is low. In contrast thereto, in the case of FIG.3B, as the peak of each curve is sharp, the number of heating lampscontributing to heat a specific zone of the wafer is small, and thus,the directivity is high.

[0014] Thus, in order to improve the directivity of the heating lamps,it is preferable to shorten the distance D. However, in a case wherethermal processing of the wafer is performed in a vacuum atmosphere(pressure-reduced atmosphere), a thickness t of the transmitting window20 made of a quarz glass should be on the order of 30 through 40 mm fora diameter thereof on the order of 400 mm, for example, so as to securea high pressure resistivity of the transmitting window 20. Thereby, thedirectivity of the heating lamps are degraded, and, also, thetemperature controllability is degraded as a result of the heat capacityof the transmitting window 20 being increased due to the increasedthickness t thereof.

[0015] In order to solve this problem, the pressure resistivity of thetransmitting window 20 may be increased as a result of shaping it to adome shape having an approximately hemisphere shape, for example, asshown in FIG. 4. However, in this case, although it is possible toreduce the thickness of the transmitting window 20 itself to the orderof 10 through 20 mm, the total height H of the dome-shaped transmittingwindow 20 is on the order of 60 through 70 mm. Accordingly, this methodcannot solve the problem in that the above-mentioned distance D shouldbe shortened.

[0016]FIGS. 5 and 6 show another example of a thermal processing systemin the related art. FIG. 5 shows a general configuration of the thermalprocessing system, and FIG. 6 shows a plan view illustrating anarrangement of heating lamps of the thermal processing system. As shownin FIG. 5, in a processing chamber 102, a ring-shaped placement table104 is provided. The periphery of the semiconductor wafer W on thebottom side thereof is made contact with the inner circumference of theplacement table 104 on the top side thereof, and, thus, the wafer W issupported by the placement table 104. This placement table 104 is fixedon a top end of a cylindrical leg part 106 which is supported by abottom of the processing chamber 109 via a ring-shaped bearing part 103.Thus, the placement table 104 is rotatable along a circumferentialdirection of the cylindrical leg part 106.

[0017] A rack 110 is provided on the inner wall of the leg part 106along the circumferential direction of the leg part 106. Further, adriving shaft 114 of a driving motor 112 provided beneath the chamber102 projects upward through the bottom of the chamber 102 in an airtightmanner. The driving shaft 114 has a pinion 116 fixed on the top thereofwhich is engaged with the above-mentioned rack 110. Thereby, the legpart 106 and the placement table 104 integral therewith are rotated.Further, a flat transmitting window 118 made of a quarz glass, forexample, is provided on the top of the processing chamber 104 in anairtight manner. Further, above the transmitting window 118, a pluralityof heating lamps 120 are provided. Then, by means of radiant heat fromthe lamps 120, the wafer W is heated to a predetermined temperature. Asa result of the placement table 4 being rotated at a time of theheating, the wafer W placed on the placement table 104 is heated whileit is rotated. Accordingly, the temperature of the wafer W is madeuniform throughout the surface thereof.

[0018] In this system, the heating lamps 120 include, as shown in FIG.6, for example, approximately spherical lamp bodies 122, and reflectiveplates 124 provided at the rear side of the lamp bodies 122 and formedto be depressed. Thereby, the radiant heat can be efficiently used.Further, in order to enable supply of large power, the lamp bodies 122include therein filaments 126 extending toward the wafer W spirally.Such a type of lamp bodies are called ‘single-end type lamp bodies’. Inthis case, the plurality of heating lamps 120 are arranged so as tocover the top surface of the above-mentioned semiconductor wafer W.

[0019]FIGS. 7 and 8 show another thermal processing system in therelated art. In this system, instead of the sphere-liked lamp bodies 122described above, rod-like lamp bodies 128 are employed in heating lamps130. At the rear side of the lamp bodies 128, reflective plates 132 eachhaving a sectional shape of approximately hemisphere are disposed. Ineach lamp body 128, a spirally wound filament 134, for example, iscontained so as to extend along a longitudinal direction of the lampbody 128, and electric terminals 136 are provided on both ends of thelamp body 128. Such a type of lamp body 128 is called a ‘double-end typelamp body’. The heating lamps 130 are disposed in parallel withpredetermined intervals.

[0020] When the sphere-shaped lamps 120 with the depressed reflectiveplates 124 are used as shown in FIGS. 5 and 6, directivity andcontrollability of the radiant heat are satisfactory. However, in thisstructure of each lamp 120, the amount of radiant heat in horizontaldirections is large, and it is reflected so as to be directed toward thewafer, and energy is lost each time of the reflection. Accordingly, alarge amount of energy is lost.

[0021] In contrast thereto, when the rod-shaped lamps 130 shown in FIGS.7 and 8 are used, a large amount of radiant heat is directly irradiatedto the wafer. Accordingly, the energy loss is relatively small. However,in this case, each lamp body 128 should cover a relatively large area ofthe surface of the wafer. Further, because the lamp body 128 is disposedacross the wafer, the directivity thereof is degraded. Accordingly, itis difficult to make the temperature of the wafer uniform at highaccuracy.

[0022] Further, in order to improve the directivity of the radiant heat,a distance D between the surface of the wafer W and the heating lamps120, for example (see FIG. 5), should be shortened so that diffusion ofthe radiant heat is made smaller, as described above with referenceFIGS. 3A and 3B. Also in this case, it can be considered to employ adome-shaped transmitting window as the transmitting window 118 in orderto reduce the thickness of the transmitting window, as described abovewith reference FIG. 4. However, as mentioned above, by such a method,the problem cannot be solved substantially.

DISCLOSURE OF THE INVENTION

[0023] The present invention has been devised in consideration of theabove-described problems, and, an object of the present invention is toprovide a system and method of thermal processing employing heatinglamps having high directivity and high temperature controllability.

[0024] A thermal processing system, according to the present invention,performs predetermined thermal processing on an approximately circularto-be-processed object, by applying radiant heat to the to-be-processedobject by means of a heating lamp system, wherein:

[0025] the heating lamp system comprises a plurality of lamps disposedconcentrically so as to correspond to the to-be-processed object; and

[0026] the plurality of lamps are controlled individually for respectivezones of the to-be-processed object.

[0027] Thereby, it is possible to heat the to-be-processed object forthe respective concentric zones, individually, for example. Accordingly,it is possible to improve the directivity of the radiant heat of thelamps and controllability of the temperature of the to-be-processedobject such as a wafer W. Further, by controlling the temperature of thewafer W for the respective concentrically divided zones of the wafer W,individually, it is possible to control the temperature of the wafer Wfor respective zones one by one, and, thereby, to make the temperatureof the wafer W uniform throughout the enter surface of the wafer W at ahigher accuracy.

[0028] Specifically, for example, because the periphery of the wafer Wmay be easily cooled naturally, a larger power is supplied to each lamplocated farther from the center of the wafer W. Thereby, it is possibleto heat the wafer W uniformly. Thus, as the lamps are disposedconcentrically corresponding to the circular wafer W, it is easy to makea control such as to make the temperature of the wafer W uniformthroughout the surface of the wafer W by controlling the powers suppliedto the respective lamps for the respective concentrically disposedzones. That is, according to the present invention, the configuration ofthe heating lamps is made to correspond to the concentric temperaturevariation characteristics/distribution of the circular wafer W.

[0029] The thermal processing system may further comprise:

[0030] a transmitting window between the heating lamp system and theto-be-processed object; and

[0031] a reinforcing member reinforcing the transmitting window.

[0032] By providing the reinforcing member, it is possible to reduce thethickness of the transmitting window effectively even in a case where aprocessing chamber is provided for sealing up the wafer W in an airtightmanner and thermal processing is performed under a reduced pressure orvacuum atmosphere therein. Accordingly, it is possible to reduce thedistance between the heating lamp system and the wafer W. Thereby, it ispossible to further improve the directivity of the radiant heat.Further, as it is possible to reduce the heat capacity of thetransmitting window due to reduction in thickness thereof, it ispossible to further improve the controllability of the temperature ofthe wafer W for the respective zones.

[0033] Furthermore, by forming, in the reinforcing member, concentricslits corresponding to the concentrically disposed plurality lamps, itis possible to efficiently utilize the radiant heat of the lamps forheating the wafer W. Furthermore, it is possible to control the heatingof the wafer W more accurately, as nothing exists between the lamps andthe wafer W other than the transparent or translucent transmittingwindow as a result of providing the slits in the reinforcing member.

[0034] Other objects and further features of the present invention willbecome more apparent from the following detailed description when readin conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0035]FIG. 1 shows a first example of a thermal processing system in therelated art;

[0036]FIG. 2 shows a second example of a thermal processing system inthe related art;

[0037]FIGS. 3A and 3B show graphs of relationship between thedirectivity of heating lamps and distance from the lamps;

[0038]FIG. 4 shows a sectional view of a dome-shaped transmitting windowin one example;

[0039]FIG. 5 shows a third example of a thermal processing system in therelated art;

[0040]FIG. 6 shows an arrangement of heating lamps of the system shownin FIG. 5;

[0041]FIG. 7 shows a fourth example of a thermal processing system inthe related art;

[0042]FIG. 8 shows an arrangement of heating lamps of the system shownin FIG. 7;

[0043]FIG. 9 shows a side-elevational sectional view of a thermalprocessing system in one embodiment of the present invention;

[0044]FIG. 10 shows a cross-sectional view of the thermal processingsystem shown in FIG. 9 taken along a line A-A;

[0045]FIG. 11 shows a plan view of a supporting frame member of thethermal processing system shown in FIG. 9;

[0046]FIG. 12 shows a plan view of an arrangement of heating lamps of aheating lamp system of the thermal processing system shown in FIG. 9;

[0047]FIG. 13 shows a plan view of another arrangement of heating lampsof a heating lamp system which also can be instead employed in thethermal processing system shown in FIG. 9;

[0048]FIG. 14 shows a plan view of another arrangement of heating lampsof a heating lamp system which also can be instead employed in thethermal processing system shown in FIG. 9;

[0049]FIG. 15 shows a plan view of another supporting frame member whichalso can be instead employed together with the heating lamp system shownin FIG. 14 in the thermal processing system shown in FIG. 9;

[0050]FIG. 16 shows a plan view of another arrangement of heating lampsof a heating lamp system which also can be instead employed in thethermal processing system shown in FIG. 9;

[0051]FIG. 17 shows a side-elevational sectional view of a thermalprocessing system in a variant embodiment of the embodiment of thepresent invention shown in FIG. 9 in which medium paths for temperaturecontrol are omitted from a side wall and a bottom plate of a processingchamber; and

[0052]FIG. 18 shows a side-elevational sectional view of a thermalprocessing system in another variant embodiment of the first embodimentof the present invention shown in FIG. 9 in which thermal processing isperformed under atmospheric pressure.

BEST MODE FOR CARRYING OUT THE INVENTION

[0053] A thermal processing system in one embodiment of the presentinvention will now be described.

[0054]FIG. 9 shows a configuration of the thermal processing system inthe embodiment of the present invention, and FIG. 10 shows across-sectional view of the same thermal processing system taken along aline A-A shown in FIG. 9. FIG. 11 shows a plan view of a supportingframe member, and FIG. 12 shows a plan view indicating an arrangement oftube-shaped heating lamps.

[0055] As shown in the figures, this thermal processing system 40includes a processing chamber 42 formed to be like a cylinder fromstainless steel, aluminum, or the like, for example. In a side wall ofthe processing chamber 42 near the top thereof, a processing gas nozzle44 for supplying a necessary processing gas into the processing chamber42 is provided, and, a discharge mouth 46 is provided in the side wallof the processing chamber 42 opposite to the above-mentioned nozzle 44.To the mouth 46, a vacuum pump or the like, not shown in the figure, isconnected, so that the processing chamber 42 can be made vacuum thereby.

[0056] In the processing chamber 42, a support ring 48 is providedacting as a placement table shaped to be a circular ring, for example,so as to support a to-be-processed object, such as a semiconductor waferW. This support ring 48 is connected to the top end of a leg part 50formed to be like a cylinder. Then, the above-mentioned support ring 48has a wafer holding part 51 formed as a result of the inner part of thetop end of the ring 48 being cut out to have an L-shaped sectioncircumferentially. The rear side of the periphery of the semiconductorwafer W regarded as the to-be-processed object is made contact with thewafer holding part 51. Thus, the wafer W is supported/held by thesupport ring 48.

[0057] As the temperature of the wafer W becomes such a high temperatureas maximum 1000° C., for example, the support ring 48 is made ofceramics superior in heat resistivity, such as SiC, for example.Further, a heat insulating material such as a quarz glass is employed asa connecting part 53 between the support ring 48 and leg part 50 for thepurpose of thermally protecting magnets or the like, described later,provided on the leg part 50.

[0058] Magnet parts 52 and coil parts 54 are provided on the side wallof the leg part 50 and the processing chamber 42 near the bottomthereof, respectively. Specifically, as also shown in FIG. 10, themagnet parts 52 include a pair of permanent magnets, for example,disposed apart from one another on the outer circumferential surface ofthe leg part 50 in directions of a diameter thereof.

[0059] The coil parts 54 include a plurality of coil units 56 disposedon an inner circumferential wall of the processing chamber 42circumferentially with predetermined intervals (electric angles). Thesecoil units 56 are set in positions such as to face the above-mentionedmagnet parts 52 with a slight gap in a horizontal level. An alternate(electric) current is caused to flow through each coil unit 56, having apredetermined phase difference, for example, in sequencecircumferentially. Thereby, a rotating magneitic field, the rotationspeed of which can be controlled, can be formed near the bottom of theprocessing chamber 42. Then, the magnet parts 52 magnetically attractedby the rotating magnetic field is attracted so as to follow the rotationof the rotating magnetic field. Accordingly, the led part 50 is rotatedthereby.

[0060] In this case, the bottom end of the leg part 50 is not connectedto the bottom of the processing chamber 42, and can float therefrom.Specifically, as shown in FIG. 9, in a middle level of the leg part 50,a circular-ring-like floating magnet part 58 is mounted and fixed to theouter circumferential wall of the leg part 50, circumferentially so asto be like a flange. The floating magnet part 58 is acircular-ring-shaped permanent magnet made from a thin plate, forexample, and extends horizontally.

[0061] It is assumed that the top side of the floating magnet part 58has an N pole while the bottom side thereof has an S pole. A magnetholding recess part 60 is formed in the inner circumferential wall ofthe processing chamber 42, extending horizontally and circumferentially,so as to hold therein the above-mentioned flange-like floating magnetpart 58, in a freely movable state.

[0062] The magnet holding recess part 60 is formed to be like a ringcircumferentially along the inner circumferential wall of the processingchamber 42. Further, a plurality of magnet units 62 are provided in themagnet holding recess part 60 at predetermined positions such as tomagnetically apply a floating force to the floating magnet part 58.Specifically, as shown in FIG. 10, the magnet units 62 include threeunits 62 along the circumferential inner wall of the processing chamber42 with equal intervals. The respective magnet units 62 include uppercoil units 62A, 62B and 62C and lower coil units 62 a, 62 b and 62 c soas to sandwich the above-mentioned floating magnet part 58 vertically.

[0063] Electromagnetic forces, for example, repellent forces, generatedby the respective coil units 62A, 62B, 62C, 62 a, 62 b and 62 c arecontrollable by control of electric currents caused to flow therethroughindividually. In this case, the electric currents are caused to flowthrough the respective coil units in directions such as to cause theelectromagnetic repellent forces to be generated thereby so as to causethese coil units to repel the above-mentioned floating magnet part 58.As a result, the leg part 50, that is, the floating magnet part 58floats. Although not shown in the figures, sensors are provided in theleg part 50 for detecting the horizontal and vertical positions of theleg part 50. Thereby, the electric currents flowing through the coilunits are appropriately controlled.

[0064] In the embodiment, the leg part 50 and support ring 48 arerotated in a non-contact state by means of magnetic floating. However,it is also possible that the leg part 50 is rotatably supported by abearing on the bottom of the processing chamber 42, and, by magnetsdisposed outside of the processing chamber 42, the leg part is rotated,through magnetic coupling. Alternatively, it is also possible that thesupport ring is rotated by a rotation shaft, shown in FIG. 2.

[0065] The top of the processing chamber 42 is open, and, at thisposition, the above-mentioned supporting frame member 66 is provided viaa sealing member 64 such as an O-ring, for example. Further, above thesupporting frame member 66, a transparent transmitting window 68 made ofquarz is mounted via a sealing member 70 such as an O-ringcircumferentially in an airtight manner. Specifically, the top surfaceof the supporting frame member 66 is in contact with the bottom surfaceof the transmitting window 68, so that the pressure resistivity of thetransmitting window 68 is improved. For example, the entirety of thesupporting frame member 66 is made of a material, such as aluminum,stainless steel or the like, which does not cause any problem such asmetal contamination or the like. This supporting frame member 66 has acircular-ring-shaped periphery, and, inside thereof, a plurality ofsupporting frames 72 are formed in parallel to each other withapproximately equal intervals, as shown in FIG. 11. In the figure, thenumber of supporting frames is 5. However, actually, it is 10 odd, forexample, corresponding to the diameter of the wafer W.

[0066] Further, although the plurality of supporting frames 72 areprovided in parallel to each other in this example, the configuration ofthe supporting frames is not limited thereto. For example, it is alsopossible that a plurality of supporting frames are providedperpendicularly to each other so as to be like a lattice. By providingthe supporting frame member 66 which supports the transmitting window 68by a plane, it is possible to maintain high pressure resistivity of thetransmitting window 68 even when the thickness t of the transmittingwindow 68 is made smaller. As the number of supporting frames 72 isincreased, the pressure resistivity of the transmitting window isimproved. However, in consideration of the amount of radiant heatgenerated by a heating lamp system 86 to be transmitted by thetransmitting window 68, it is preferable to set the opening ratio (ratioof the area for which the radiant heat can pass through) to be equal toor larger than 60%. In this case, specifically, for example, the widthL1 of each supporting frame 72 is on the order of 12 mm, while theinterval L2 between each adjacent supporting frames 72 is on the orderof 16 mm.

[0067] Further, as shown in FIG. 11, temperature controlling mediumpaths 74 are formed in the supporting frames 72 and the periphery of thesupporting frame member 66 through drilling by means of a drill. One endof each of the paths 74 communicates with an inlet header 78 having amedium inlet 76, in common. Further, the other end thereof communicateswith an outlet header 82 having an outlet 80, in common. Thereby, whenheating is performed, a hot water or the like is caused to flowtherethrough. When cooling is performed, a cold water or the like iscaused to flow therethrough. Thus, the supporting frame member 66 andthus transmitting window 68 are heated or cooled so that temperaturecontrol therefor can be performed. In this case, specifically, forexample, the diameter L3 of each medium path 74 is approximately 4 mm.

[0068] Above the transmitting window 68, a lamp box 84 is provided. Inthe lamp box 84, the above-mentioned heating lamp system 86 is provided,and heats the semiconductor wafer W inside the processing chamber 42 bymeans of the radiant heat therefrom. Specifically, as shown in FIG. 12,the heating lamp system 86 includes a plurality of tube-like heatinglamps 90, each having electric terminals 92 at both ends, disposedconcentrically so as to correspond to the semiconductor wafer W havingan approximately circular shape. In the example shown in FIG. 12, aplural types of pairs of approximately semicircular tube-like double-endheating lamps 90 having different bending radii, having approximatelysemicircular shapes and having arc shapes, are disposed concentricallyso as to correspond to the wafer W having an approximately circularshape. The electric terminals 92 of the respective heating lamps 90 areconnected with electric power supply wires (not shown in the figure).Inside of each of the tube-like heating lamps 90, a filament 94 (seeFIG. 9) is provided so as to be connected between the two terminals 92.Thus, each heating lamp 90 is a halogen lamp, for example.

[0069] The above-mentioned concentrically disposed tube-like heatinglamps 90 are used for heating a plurality concentric zones, that is, aninner zone 96A, a middle zone 96B and an outer zone 96C, of the surfaceof the wafer W, as shown in FIG. 12, for example. In the example of FIG.12, the heating lamps 90 are disposed so that a single circle of lamps90 are provided for the inner zone 96A, double circles thereof areprovided for the middle zone 96B and double circles thereof are providedfor the outer zone 96C. However, actually, further larger number ofdifferent-diameter circles of lamps are provided therefor.

[0070] Then, above each of the respective tube-like heating lamps 90, areflective plate 98 having an approximately semicircular section ortrapezoidal section, as shown in FIG. 9, is mounted. Thereby, also thelight reflected thereby is made to be applied to the wafer W. In FIG.12, indication of the reflective plates 98 is omitted.

[0071] The above-mentioned tube-like heating lamps 90 are connected witha lamp control part 200 for each zone. Further, on the bottom of theprocessing chamber 42, a plurality of radiation thermometers 202corresponding to the respective zones are provided, as shown in FIG. 9,and, the temperatures of the heating lamps 90 are controlled for therespective zones according to a feedback manner based on the wafertemperatures obtained through the respective radiation thermometers 202,respectively, individually. Thus, the temperature of the wafer W ismaintained to be a predetermined uniform temperature throughout theentire surface of the wafer W especially along the radial directions.

[0072] Further, as shown in FIG. 9, medium paths 204 are formed in theside wall and bottom plate of the processing chamber 42 approximatelythrough the entire periphery of the processing chamber 42 for passing atemperature controlling medium therethrough. From a medium inlet 204Aprovided at a part of the side wall, the temperature controlling mediumis provided into the medium paths 204, and, from a medium outlet 204Bprovided at another part of the side wall, the temperature controllingmedium is discharged. This temperature controlling medium may be thesame as the temperature controlling medium which is used to flow throughthe medium paths 74 provided in the supporting frame member 66.According to a request concerning a process to be performed on the waferW, the temperature controlling medium is used for cooling, or heatingthe processing chamber 42 so as to control the temperature thereof. Itis possible to provide an independent systems such that thereby thetemperature controlling medium to flow through the medium paths 74 ofthe supporting frame member 66 and the temperature controlling medium toflow through the medium paths of the processing chamber 42 can becontrolled in temperature thereof individually. Instead, it is alsopossible to provide a system such that the temperature controllingmedium is to flow through the medium paths 74 and 104 continuously.

[0073] In FIG. 9, a gate valve 206 is opened/closed when thesemiconductor wafer W is conveyed into and out from the processingchamber 42. Further, although not shown in the figure, a lifter pin forlifting/lowering the wafer W is also provided at a bottom part of theprocessing chamber 42 which works during the conveyance of the wafer W.

[0074] Operation of the thermal processing system in the embodiment ofthe present invention described above will now be described.

[0075] First, the semiconductor wafer W is brought in into theprocessing chamber 42 which is maintained in a vacuum condition, from aload lock room or the like, not shown in the figures, via the openedgate valve 206. This wafer W is placed on the wafer holding part 51 ofthe support ring 48 by means of the above-mentioned lifter pin, and isheld thereby.

[0076] Then, after thus bringing in of the wafer W is completed, thegate valve 206 is closed so that the processing chamber 42 is sealed,and, also, a predetermined processing gas corresponding to a process tobe performed on the wafer W is provided into the processing chamber 42via the processing gas nozzle 44 while the pressure in the processingchamber 42 is being reduced to produce a vacuum therein. Then, thepredetermined process pressure is maintained in the processing chamber42. For example, in a case where a deposition process is performed onthe wafer W as the thermal processing, a deposition gas is provided intoa processing space S in the processing chamber 42 together with acarrier gas such as N₂ gas.

[0077] Then, the heating lamp system 86 provided at the top of theprocessing chamber 42 is driven so that the heating lamps 90 are turnedon. Then, heat rays emitted by the heating lamp system 86 are incidentinto the processing space S through the transparent transmitting window68. Then, the heat rays are applied onto the top surface of thesemiconductor wafer W, and, thereby, the surface of the wafer W isheated into a predetermined temperature. Then, it is maintained in thistemperature.

[0078] Simultaneously, the respective coil units 56 of theabove-mentioned coil parts 54 provided at the lower part of the insideof the processing chamber 42 have the alternate (electric) currentshaving predetermined phase differences flowing therethrough in sequence.Thereby, the rotating magnetic field having the predetermined rotationspeed is formed inside the processing chamber 42 (see FIG. 10). Then,the magnet parts 52 of the leg part 50 move so as to follow the rotatingmagnetic field. Accordingly, the leg part 50 and support ring 48 rotatethereby. As a result, the semiconductor wafer W held by the support ring48 is rotated during the thermal processing interval. Thereby, acondition in that the temperature of the wafer W is made uniformthroughout the surface of the wafer W is maintained.

[0079] Further, at this time, the upper and lower coil units 62A, 62B,62C, 62 a, 62 b and 62 c of the three respective floating magnet parts62 provided in the magnet holding recess part 60 of the processingchamber 42 have electric currents flowing therethrough so that therepellent forces are generated between these coil units and theflange-shaped floating magnet part 58 located between the coil units. Bythe repellent forces, the flange-shaped floating magnet part 58 and theleg part 50 integral therewith float. Accordingly, the leg part 50 isrotated in a condition in which it floats magnetically. As a result, theleg part 50 is rotated stably in the magnetically floating condition.Thus, the leg part 50 is supported without using any bearing or thelike, in a non-contact condition. As a result, problems such asgeneration of particles due to friction, metal contamination and soforth can be avoided.

[0080] Further, the transmitting window 68 is reinforced as a result ofthe bottom surface of the transmitting window 68 being firmly supportedby the supporting frame member 66 having the plurality of supportingframes 72 in a surface contact condition so that the pressureresistively of the transmitting window 68 is considerably improved.Accordingly, it is possible to reduce the thickness of the transmittingwindow 68. For example, in the system in the related art shown in FIG.5, the thickness of the transmitting window should be 30 through 40 mmfor the diameter of 400 mm. However, in the embodiment of the presentinvention described above, merely the thickness on the order of 2through 5 mm is sufficient. Accordingly, it is possible to reduce thethickness t of the transmitting window 68 remarkably. By reducing thethickness t of the transmitting window 68, it is possible to reduce thedistance D between the surface of the wafer W and the heating lampsystem 86. Thereby, it is possible to improve the directivity of theradiant heat from the heating lamp system 86.

[0081] Furthermore, the medium paths 74 are provided in the supportingframes 72 of the supporting frame member 66 as shown in FIG. 11. Bycausing the temperature controlling medium such as coolant, that is,cooling water, for example, to flow therethrough, when cooling isperformed, for example, it is possible to cool the supporting framemember 66 and thus the transmitting window 68 thereabove to atemperature on the order of the room temperature of the processingchamber 42. Accordingly, occurrence of metal contamination due tomelting of the supporting frame member 66, adherence of reactionby-product or the like to the bottom surface of the transmitting window68 or the surface of the supporting frame member 66, and so forth,especially in a case of deposition profess, can be avoided. Further, bycontrolling the cooling temperature to a fixed temperature bycontrolling the temperature and/or flow rate of the coolant, thermalinfluence given to the wafer W by the supporting frame member 66 andtransmitting window 68 can be made to be always constant. Accordingly,it is possible to eliminate variations in degree of thermal processingperformed on the respective wafers W, one by one, which may be easilyaffected by the temperature sensitively. Thereby, it is possible toremarkably improve repeatability. In a case where the transmittingwindow 68 should be heated due to a request according to a process, aheat medium is caused to flow through the paths 74.

[0082] Similarly, the temperature controlling medium, for example, acoolant such as a cooling water, when cooling is performed, is caused toflow through the medium paths 204 provided in the side wall and bottomplate of the processing chamber 42 described above. Thereby, the sidewall and bottom plate of the processing chamber 42 is cooled so thatalmost all the surfaces of the side wall and bottom plate of theprocessing chamber 42 enter a completely cold wall condition. Thereby,it is possible to avoid adherence of reaction by-product or a depositionfilm, produced in a case of a deposition process or the like, to theinner wall of the processing chamber 42. Also in this case, bycontrolling the temperature and/or flow rate of the coolant so that thecooling temperature is constant. it is possible to improve therepeatability of the thermal processing performed on the wafer W, by thereason same as that mentioned above.

[0083] Thus, the top, that is, the transmitting window 68, side wall,bottom wall and so forth of the processing chamber 42 are prevented frombeing adhered to by a reaction by-product, a deposition film or thelike. Accordingly, it is possible to reduce the amount of particlesproduced, and it is possible to reduce the frequency of times ofcleaning operations performed on the processing chamber 42 and so forth.

[0084] Specific controlling temperatures of the transmitting window 68,side wall and bottom plate of the processing chamber 42 in a case wheredeposition processing is performed as thermal processing will now bedescribed. In order to avoid adherence of reaction by-product or adeposition film, the temperature is maintained at on the order of 150through 500° C., for example, in order to avoid adherence of NH₄Cl orthe like which is reaction by-product in a case of deposition of siliconnitride film by using SiH₂Cl₂ and NH₃. The temperature is maintained aton the order of 0 through 400° C., for example, in a case of depositionof polysilicon film by using SiH₄, or Si₂H₆. The temperature ismaintained at less than 150° C., for example, in order to avoidadherence of a raw material gas or a liquefied by-product in a case ofdeposition of Ta₂O₅ film using Ta₂(OC₂H₅)₅ (penthaethoxytantal) or thelike. The temperature is maintained at on the order of 100 through 200°C., for example, in order to avoid adherence of TEOS itself in a case ofdeposition of SiO₂ film by using TEOS.

[0085] In the above-described embodiment, the heating lamp system 86includes the concentrically disposed tube-like heating lamps 90 formedto have approximately semicircular shapes, and, also, the powerssupplied to the lamps 90 are controlled for the respective zones,respectively, independently through control by the control part 200.Accordingly, first, in comparison to the case of employing thesingle-end lamps shown in FIGS. 5 and 6, a large amount of radiant heatemitted from the lamps 90 is not reflected but directly applied to thewafer W. Accordingly, it is possible to efficiently heat the wafer W.

[0086] Further, as mentioned above, the periphery of the wafer W mayhave a relatively large amount of heat discharged therefrom incomparison to the center thereof. In order to deal with such asituation, in the above-described embodiment, as a result of the lamps90 being disposed concentrically as mentioned above and the supplypowers being controlled for the respective concentric zones,respectively, individually, it is possible to improve the directivitythereof, and, also, to perform temperature control at high accuracyalong the radial directions of the wafer W. Thus, it is possible tocontrol the temperature of the surface of the wafer W to be uniformthroughout the surface of the wafer W effectively. The above-mentioneddirectivity can be improved also by reducing the thickness t of thetransmitting window 68 as mentioned above. Accordingly, the directivitycan be further improved.

[0087] In the example of FIG. 12, each heating lamp 90 is formed to belike a semicircle. However, the opening angle of the arc shape thereofis not limited thereto, and, it is possible to form each heating lamp 90into an arc shape having the opening angle of 90° (¼ arc), an arc shapehaving the opening angle of 60° (⅙ arc), or the like. Further, it isalso possible that tube-like heating lamps having arc shapes havingdifferent opening angles for different zones are combined.

[0088] Further, it is also possible to employ approximately circularring-shaped tube-like heating lamps 90A in each of which only a part ofa circle is cut out, as shown in FIG. 13.

[0089] Further, as shown in FIGS. 14 and 15, in the supporting framemember 66, supporting frames 72A including temperature controllingmedium paths 74A may be shaped so as to prevent these supporting frames72A from blocking the radiant heat emitted from concentrically disposedarc-shaped tube-like heating lamps 90C shown in FIG. 14. In thisexample, as shown in FIG. 15, slits 72B are formed in locations such asto correspond to the locations of the respective arc-shaped tube-likeheating lamps 90C shown in FIG. 14, respectively. Accordingly, theradiant heat emitted by the lamps 90C can effectively reach the wafer Wthrough the transmitting window 68 and thus be efficiently utilized forheating the wafer W. Further, in the configuration shown in FIGS. 14 and15, as each lamp 90C faces the wafer W without being blocked by thesupporting frames 72A through the respective slit 72B, it is possiblefor each lamp 90C to directly heat a respective zone of the wafer W.Accordingly, it is possible to control the temperature of the wafer W ata higher accuracy. Thus, the temperature controllability of the wafer Wis improved.

[0090] Further, as shown in FIG. 16, it is also possible to employ aplurality of straight-rod-shaped tube-like heating lamps 90B, which maybe general-purpose ones and thus inexpensive, disposed approximatelyconcentrically for the respective zones. In this case, the length ofeach straight-rod-shaped heating lamp 90B should be different so as tocorrespond to the curvature of the respective zone.

[0091] Further, it is also possible to appropriately combine thesestraight tube-like heating lamps 90B with the above-mentioned arc-shapedtube-like heating lamps 90, 90A.

[0092] Further, it is also possible to omit the provision of the mediumpaths 204 from the side wall and bottom plate of the processing chamber42, as shown in FIG. 17 in a situation in which adherence of depositionfilm or reaction by-product is not so serious and/or not so problematicaccording to a process.

[0093] Further, in the above-described embodiment, processing isperformed under a reduced pressure atmosphere or a vacuum atmospheresuch as in a CVD process. However, in a case where thermal processing isperformed under an atmospheric pressure atmosphere or an atmosphere nearthe atmospheric pressure atmosphere, such as in an annealing process,diffusion process and so forth, it is not necessary to provide thesupporting frame member 66 to increase the pressure resistivity of thetransmitting window, shown in FIG. 9. In this case, as shown in FIG. 18,the transmitting window 68 is set directly at the top of the processingchamber 42 only via the O-ring 64. Thereby, it is possible to furtherreduce the distance D between the surface of the wafer W and the heatinglamp system 86. Accordingly, the directivity of the heating lamp system86 is further improved, and thus, it is possible to further improve theaccuracy of temperature control for the respective zones.

[0094] Further, in the above-described embodiment, the supporting framemember 66, transmitting window 68 and heating lamp system 86 are set atthe top part of the processing chamber 42. However, it is also possibleto set them at a bottom part of the processing chamber 42, or to setthem at the top part and bottom part, respectively.

[0095] Further, although the to-be-processed object is a semiconductorwafer W in the embodiment, it is also possible to apply the presentinvention for a glass substrate, a LCD substrate, or the like.

[0096] Further, any thermal processing system according to the presentinvention can also be applied for a deposition process such as a CVDprocess, an oxidation process, and so forth, other than theabove-mentioned annealing process.

[0097] It is also possible to rotate the heating lamp system withrespect to the placement part of the wafer W in each embodiment of thepresent invention. Thereby, it is possible to heat the wafer W furtheruniformly.

[0098] Further, the present invention is not limited to theabove-described embodiments, and variations and modifications may bemade without departing from the scope of the present invention.

[0099] The present application is based on Japanese priorityapplications Nos. 2000-119997 and 2000-119998, both filed on Apr. 20,2000, the entire contents of which are hereby incorporated by reference.

1. A thermal processing system performing predetermined thermalprocessing on an approximately circular to-be-processed object, byapplying radiant heat to the to-be-processed object by means of aheating lamp system, wherein: said heating lamp system comprises aplurality of lamps disposed concentrically so as to correspond to theto-be-processed object; and said plurality of lamps are controlledindividually for respective zones of the to-be-processed object.
 2. Thethermal processing system as claimed in claim 1, wherein said zones haveconcentric circular shapes, respectively.
 3. The thermal processingsystem as claimed in claim 1, wherein said plurality of lamps comprisearc-shaped lamps.
 4. The thermal processing system as claimed in claim1, wherein said plurality of lamps comprise rod-shaped lamps.
 5. Thethermal processing system as claimed in claim 1, wherein said pluralityof lamps are disposed so as to form a plurality of concentric circleshaving different radii.
 6. The thermal processing system as claimed inclaim 1, further comprising: a transmitting window between said heatinglamp system and the to-be-processed object; and a reinforcing memberreinforcing said transmitting window.
 7. The thermal processing systemas claimed in claim 6, wherein said reinforcing member comprises aplurality of members disposed in parallel.
 8. The thermal processingsystem as claimed in claim 6, wherein said reinforcing member isconfigured so that concentric slits are formed therein corresponding tothe concentrically disposed plurality of lamps.
 9. The thermalprocessing system as claimed in claim 8, wherein each slit has an arcshape.
 10. The thermal processing system as claimed in claim 6, furthercomprising a sealed processing chamber in which the to-be-processedobject is sealed and processed under a reduced pressure atmosphere,wherein: said transmitting window is provided as a part of saidprocessing chamber in an airtight manner; said heating lamp system isprovided outside of said processing chamber and applies the radiant heatto the to-be-processed object inside of the processing chamber throughsaid transmitting window.